Buggy BAG Motors
 

Hello Everyone,

We're running one of our BAG motors at about 80% power into a 1:1 VEX VersaPlanetary.

Earlier today, it appeared that we had a BAG motor give out on us. We can't tell if it's a loose connection in the motor's internals, or running the system with 1:1 wasn't the wisest idea (with 2, 3-7/8 blue banebot wheels).

Anyone experience any sort of performance issue with a similar setup? We're wondering if we need to perhaps reconsider our setup or perhaps it was a one-time occurrence.

- Sunny G.

Re: Buggy BAG Motors
 

We had one get a bit flaky on us. Low torque, and if it stopped in a certain place it wouldn't start again, but if it ran continuously it would keep on running. Took it apart (very nicely made motor inside) and it seemed like the brushes may have been hanging up a little bit, took them out, put them back in, slid them back and forth a little bit, and it seems fine.

Re: Buggy BAG Motors
 

BAGs are giving out on us too. In a 30:1 VersaPlanetary gearbox. We found that we could change rpms by moving around the leads. The motor would stop running for a short time then turn on again. We're switching to an RS550.

Re: Buggy BAG Motors
 

We still haven't had issues with either our practice shooter or our real shooter but 2587 did have an issue at the end of week 6. So I'm not sure what the difference is. We also use ours to collect so we stall it pretty regularly when testing things and they have all been fine so far.

Re: Buggy BAG Motors
 

We had an issue with a couple. We found that the coating on two of the wires going to the commutators wasn't stripped off before they were soldered together. We stripped off the coating and re-soldered the wires to the commutators and all was well.

Hope this helps


We didn't think about making a deal of it as we didn't find anyone else with the issue

Re: Buggy BAG Motors
 

We had the exact same symptoms, except in the 1:1 configuration. The max rpm would sometimes be different, and we tried adjusting victors, when finally the motor just wouldn't move when we applied power. Looks like we're packing some RS 545's before the team leaves for Palmetto tomorrow.

I'll see what I find when i take one apart. Has anyone else been experiencing similar symptoms?

Re: Buggy BAG Motors
 

987 has had similar issues to what you are all describing on 3 of our BAG motors. VEX support has been extremely helpful via phone and email support and we are sending these back. Agree with sanddrag that the internals are high quality. We had the issues when attached to planetary gearboxes and under no-load situations.

Re: Buggy BAG Motors
 

We haven't had any particular problems we weren't able to solve. As well as what's stated above, make sure that the set screw clamping the gearbox and motor is tight (and hopefully still there!). Tightening (or replacing) them has solved our issues.

Re: Buggy BAG Motors
 

Wow, I thought we were the only ones. We have been having the same issues with the BAG motor on our intake. Just changes rpm at will and it seems like moving the wires going into the motor have an effect on it as well.

Re: Buggy BAG Motors
 

We also have had some quirky bag motors. I'm not too sure on the specifics, but some of the issues seemed to be due in part to unsupported motor leads being pulled away from the case. We added a simple relief loop to the wiring and that seems to have done the trick.

Otherwise, BAG's are pretty awesome.

Re: Buggy BAG Motors
 

We've been experience the following
- They run with a variance of RPM when they do run.
- Sometimes after running once they don't turn back on. We go and spin the wheel lightly and it kicks on. (probably the brushes hanging up)
- We've had this issue with about 6 of them.

Obviously the risk of this happening is high and we don't want it happening during our matches so we have switched them out to the RS550.

Glad we weren't the only ones having issues.

Re: Buggy BAG Motors
 

All,

This has been brought to our attention, but we have taken apart several motors here in our inventory and have not found any of the problems you are describing. The best way we can help solve this issue is for you to work with our customer service department to send us your bad motors so we can investigate. We will send you out replacement motors immediately as long as you agree to send back your bad motors within one week.

Moving the wires to change RPMs, based on the construction method of this motor is highly unlikely to me so there must be something else. Please know that the construction method of the BAG motor internals is exactly the same as the CIM motor with smaller parts. The leads are mechanically isolated from the electrical connection to the brushes.

The most likely scenario is that the brushes are hanging up on the commutators, but we can only solve it if we get some motors back. We have plenty in stock and can ship you replacements same day.

EDIT: UPDATE - We are pulling all of the BAG motors from inventory and 100% inspecting for the lost commutator issue. I will send updates as we figure out the % of motors with this issue.


Paul

Re: Buggy BAG Motors
 

I believe this is the issue. In both cases that I can recall with our BAG motors, the motor was able to spin again once we rotated the shaft a small amount by hand.

I will find our bad BAGs and send them back. Thanks!

Re: Buggy BAG Motors
 

We had similar issues with 2 motors.

We took one apart and didn't see anything obvious, but it was late so we put a Mini CIM in its place (they're super easy to mount to the Versaplanetaries) and were happier with performance anyway.

Re: Buggy BAG Motors
 

So here is an update: We have a few of the bad motors back from customers and they display the same symptom. I will try to explain briefly.

There are 7 commutators on the BAG motor and two brushes. For those not familiar with how a DC motor works, the commutators are the things that spin with the rotor (shaft) and contact the brushes to generate the magnetic field.

In the bad BAG motors, there is an open connection between the two wires that make up the winding. This results in one set of 3 commutators disconnected from a set of 4 commutators. When one brush is contacting only within the set of 3 and the other brush is contacting only within the set of 4 the motor will receive no current and not spin. This symptom will only show if the motor stops at a spot described above.

We are inspecting all of our BAG motors in inventory to find any motors with this condition. We have inspected about 500 so far and have not found any bad motors.

What we don't know is if this is a condition caused by use or a problem right out of the box. Our theory is that the problem is right out of the box so our inspections should eliminate this issue.

You can inspect your own motors by using a ohm meter on the two leads and spinning the motor slowly. If the resistance goes into the k Ohm or M Ohm range, then you have the problem.

We will replace all motors with this condition if you contact our customer support at support@vexrobotics.com.

Re: Buggy BAG Motors
 

I'm seriously impressed by the speed of the response from the people at VEX!

Fingers crossed ours are working perfectly so far!

- Bochek

Re: Buggy BAG Motors
 

For both of our problematic motors, we ran for several hours before the issue appeared. Once it appeared, we observed a ~1 in 5 chance that the motor would not start from a given stopped position. The motors were assembled and disassembled from their respective mechanisms/transmissions several times as well before the problem arose, so it is possible that some combination of operation and handling contributed to the issue.

Re: Buggy BAG Motors
 

We've had two go bad more or less immediately after assembling them to a Versa and running them lightly. Another has been in use with no issues.

Re: Buggy BAG Motors
 

Nice to see the quick replies.

Our issues have also been with motors that seen extensive use for a few hours/testing sessions, and then they just conk out.

Oh well, nothing to do until after our week 1.

- Sunny G.

Re: Buggy BAG Motors
 

We believe this is isolated to a specific date code. we are still investigating, but it will be very helpful to let us know your date code. The code is
"YWWD" - Year, Week, Day all numbers. The last two letters are the actual factory. All of our motors are made in the same factory so that part of the date code is not relevant.

If you can e-mail me paul_copioli [the at symbol] vexrobotics [dot] com your date codes of bad motors, then that may help expedite the process.

Thanks,
Paul

Re: Buggy BAG Motors
 

Paul, would it help if we organized an informal check of motors at some of the regionals? I know my team isn't using the BAG motor this year, but I want to check ours the next time I'm at our build space (if only to avoid issues if we try to use it in the future), and it sounds like it would be quick and easy to walk around the regional with a multimeter and check any BAG motors that are there.

Re: Buggy BAG Motors
 

We're using a three and have some spares as well. I don't think we have any problems. The 1:1 BAG on our shooter tops at 11000 RPM, but I figured that was from loading. I can't check any till Lone Star, but I'll be sure to check them there.

Re: Buggy BAG Motors
 

Anyone else have further problems? We have had 4 out of 5 fail.

Vex customer service has been great and we have more on the way.

I'm hoping we have just had bad luck and others are not having as many troubles as ours.

If people tell me they worked well for them during week one I'll be much happier.

Re: Buggy BAG Motors
 

We've had the failures and have since swapped everything to 550's which brings up another problem in that there are no piloting features for the 550's on the versaplanetaries so it takes a great deal of effort and fiddling with alignment to get the planetaries to not bind.

The low prices are great but I have to say all of the problems encountered thus far are not leaving a great impression for anyone I have been in contact with.

Re: Buggy BAG Motors
 

I checked the three I had on had with the resistance check that Paul suggested, and all three of them work (Highest reading I could get was 80 ohms). Unable to check the 3 that may have been buggy, as they're inside the bag itself.

Re: Buggy BAG Motors
 

Same,

We had 3/3 bags just fail over the course of the regional. Just ended up switching to RS Motors/AM motors.

Will be sending motors back to VEX sometime this week.

-RC

Re: Buggy BAG Motors
 

Sean,

I would like to know more about all the problems you have been having with the VEXpro items. Can you please either PM me or e-mail me at paul_copioli <the at symbol> vexrobotics.com? We have received very little complaints about the VersaPlanetary this season so I am interested in what problems you are hearing about or witnessing.

The Versaplanetaries purposely do not have pilots because the motor shaft is supposed to be the pilot. If you follow the procedure in the user's guide you should not get any binding between the motor and the gearbox. This motor mounting technique is very common with industrial servo motors and does not require a motor pilot.

With regards to the BAG motor issue, we are still working on root cause analysis, but the leading suspect is too much tension on the automatic motor winding machine. This can cause elevated stress in the copper wire. We have not finalized our findings yet, but we are working as quickly as possible on getting to the bottom of this problem. However, we have not received any motors back from customers yet and we are having a hard time reproducing the problem here. As soon as we get more failed units we can try to get to the bottom of this as quickly as possible.

Paul

Re: Buggy BAG Motors
 

I have to say I love the vex planetary gearboxes. Not having to press a gear on the motor using a force just lower than what is required to bend the shaft, turning the motor into trash is great. You do have to use an allen wrench in good shape to tighten the set screw though.

To stay on topic, we have not unbagged our bag motors yet.

Re: Buggy BAG Motors
 

Paul,

Thanks for the quick reply to everyone and the updates on this issue, awesome customer service! I will try to locate the BAG motor we removed a few weeks ago due to a similar failure and ohm it out to see if it has the issue.

Re: Buggy BAG Motors
 

We also had a couple more BAG motors fail over the weekend, and replaced them with RS550s. There is now only one BAG on the machine, and we will swap it out during our unbagging window before our next district event (since we bought all of our BAGs in a couple of bulk purchases, the odds seem fairly high that it will fail eventually).

We 3D printed ABS spacers to help pilot the 550s into the VersaPlanetary motor plate since even when we followed the directions as closely as possible, we were unable to obtain a gearbox that didn't bind, make clicking noises, or wobble when run. The issue (I think) is that mounting the motor concentric to the motor plate is difficult because the holes are too large to pilot the RS550's M3 bolts. Leaving the motor bolts loose ensured that we ran without binding or clicking, but resulted in a vibrating motor.

Regardless, with the spacers, installing a 550 is a breeze and everything runs smooth as butter. The VersaPlanetaries are a fantastic gearbox once you get them together! There's a reason 341 has 5 of them on our robot :)

I realize there is nothing you guys can do about the BAG motors without some failed units, so I will make some time this week to round up our problematic ones and send them your way.

Re: Buggy BAG Motors
 

Agreed. We found a metric allen wrench that seems to fit better than the recommended standard allen wrench size. I forget the sizes now. We wound up rounding out a couple of set screws until we got the hang of it. If there was one improvement I would recommend to the VersaPlanetaries it would be to simply drop a few spare set screws in the bag of small parts.

BTW: We had 3 "bad" BAG motors that developed the issues described in this thread. I contacted Paul as requested and they are send out replacements right away. In the mean time they emailed me an overnight shipping label and I have shipped them back our 3 "bad" BAG motors for testing. Hopefully this will provide some insight into the problem. I can't say enough good things about VexPro and the IFI guys customer service and how they are handling this issue. Thanks guys!

Re: Buggy BAG Motors
 

For all applications that use Allen keys, I personally suggest these:

http://www.mcmaster.com/#high-torque-hex-keys

They are only marginally more expensive than regular Allen keys, but they are awesome. I have yet to see one strip after using them for several years, even extremely small ball-point sizes like 5/64".

In addition, because they have a better contact profile against the hex sockets in the screws, they reduce the chances that you will accidentally strip a screw. I have also seen screws that were "stripped" being easily removed/tightened with these high-torque Allen keys.

Re: Buggy BAG Motors
 

Thanks for the heads up on the High-Torque Allen wrenches. I'll add some to my next McMaster order and give them a try.

Re: Buggy BAG Motors
 

Chuck I've been using them all this year and they have been great. Buy the sizes you use commonly in bulk. They're worth it.

Re: Buggy BAG Motors
 

Paul, our shooter failed twice in eliminations at FLR -- not positive it was the BAG motors (which we had already checked for dead spots before installing them as replacements for the bad ones), but we're going to pull them once we get the robot out of the bag at Buckeye, and I'll send them your way. I'd love to hear what you find with those two in particular, as they tested good before use. (I'm not saying the failure was the motors. I can't figure out what else it could possibly be, as our shooter worked great all through quals and nothing changed, but at the very least it will be another data point for you guys as you work through this issue).

Thanks for your prompt attention to the matter. Your customer service is great! (As are your mecanum wheels and versaplanetary gearboxes!)

Re: Buggy BAG Motors
 

We ran into the same issues. I PM'd Paul about it, and he says the runout on the RS-550 shaft is horrible, which would explain things. What does your magic spacer look like? Can you post it here or on Thingiverse?

BAG motor problem
 

So i have a strange motor problem, the BAG motor is connected to a spike relay - i turn the spike relay on and sometimes the motor docent spin. I have to give the motor a push to get it going.

the batteries are fresh and the motor has no load. i checked all connections and nothing seems to be loose.

Re: BAG motor problem
 

See this thread:
http://www.chiefdelphi.com/forums/sh...hreadid=114411

Re: Buggy BAG Motors
 

We made a couple of different types of spacers to play around with, but all of them worked. The simplest one was simply a 3D printed "washer" that was a tight slip fit inside the motor plate and on the boss of the RS550. We also made a more complex part that additionally piloted the RS550/Motor Plate assembly to the gearbox itself, but this didn't seem any better/worse.

Dustin will post the drawings as a white paper.

Runout in the RS550 shafts sounds like it is the main culprit, and would explain the vibration issues we see when the shaft alone provides piloting.

Re: Buggy BAG Motors
 

Hopefully today. Heh. On account of there's this Lone Star Regional tomorrow and the 3D printer is at work and all...

I could draw it myself, but I don't have the parts available to check fits. Speaking of, what did you guys print this on? A commercial printer, or a Reprap derivative?

Re: Buggy BAG Motors
 

Had there been any verification yet if this is caused by use or if it happens fresh out of the box? I'm wondering how best to help teams who may encounter this at my regional this weekend.

Re: Buggy BAG Motors
 

In our experience it happens after several hours of use. Every one of our BAGs worked great on the bench, and in the first couple hours of testing.

Re: Buggy BAG Motors
 

Kevin, the files you are looking for are in the white paper here:

http://www.chiefdelphi.com/media/papers/2782

Re: Buggy BAG Motors
 

We've encountered both. We had several "test bad" right out of the box, so didn't use them. Unfortunately, we thought a "tested good" BAG would prove reliable, but at this point I would not be comfortable saying that is the case.

Re: Buggy BAG Motors
 

The only valid test is to run it for a good while several times. I have one that is used all the time and has never failed. While this is OK for teams with practice robots like ours, it will be difficult for teams that don't.

Re: Buggy BAG Motors
 

Right-o. The first thing we did was test the resistance through the windings as we turned the output shaft very slowly, to see if there was a dead spot. The second thing we did was put them on and run them over and over again...

...then we played nine qualifying matches with them with no problems...

...then they exhibited the behavior we saw on our practice robot during autonomous in 2/3 of our quarterfinal games -- including our ability to fire the disks immediately in teleop after giving the robot a bump against the pyramid.

Bad timing, I guess. When we get to Buckeye we're replacing them with other motors, and shipping these ones (as well as the other bad ones) back to IFI for analysis.

Re: Buggy BAG Motors
 

Kevin, I hope you were able to download the files successfully.

The spacers were printed on a Fortus FDM 400mc (Large, not that it really maters) from ABS-M30 Material. Technically the machine is 'Production Grade', but I'd imagine just about any printer could knock these out. Worst case would be that the printer doesn't hit the required accuracy - IIRC, the spacers out of the Fortus ran something like +/- .002 - so you might need to sand or tweak the parts a bit for a good fit.

Re: Buggy BAG Motors
 

Not criticisizing you for choosing to 3d print these, but for teams reading wanting to make similar parts, they could easily be turned on a lathe out of plastic really fast.

Re: Buggy BAG Motors
 

Adam, you're right. In the white paper post, I mention alternative methods of making the more simple of the two spacers, the most obvious of which being to turn them down on a lathe. I'd imagine that some .75" OD, .5" ID ABS Tubing would do the trick - turn the OD down to .745" (18.9mm) or so and open the ID up to .515" (13.1mm) and you should be good to go. At the time, printing them was both more cost effective (made 7 spacers using $1 dollar or so of ABS) and more time friendly. (~30minutes total)

Re: Buggy BAG Motors
 

Post was up in time, I was late. Working too late to finish up a project so I can play tomorrow, no time to warm up the printer and all that. It's a Stratasys uPrint. We rarely run it, so printing something is the involved process of booting and warming it up and reloading the material* and all that. By the time all that's done, even the smallest of parts takes an hour to print. So no spacers for me at LSR. If it's a problem, I'll print some out for Alamo.

*Thou shalt always unload the support material when not using the printer. And store it in an airtight bag. Otherwise it absorbs moisture and doesn't work worth crap. Some co-worker learned us that one, printing something and leaving the machine loaded. I found out several weeks later and it was already too late.

Re: Buggy BAG Motors
 

We've only experienced this problem on our Dimension SST 768 with a VERY old cartridge. We've had cartridges in for 6 months and been fine. Should we be really be removing it and sealing it in a bag every time? I feel like that's too often.

Re: Buggy BAG Motors
 

Depends on the cartridge, I'm sure. I don't think the Stratasys uPrint ones seal very well. Also, I live in Houston, a highly urbanized swamp. I just know a reel of support material was sitting in the machine for close to a month, and the next time I tried printing with it, all I got was bubbles.

Re: Buggy BAG Motors
 

Greetings,
Our team decided to use a bag motor for our shooter connected through a versa gear box modified to a 1:1 ratio. It experienced the same issues mentioned previously in the thread: one would not start up when required and another would run a varied RPM's. It is rather frustrating, honestly. We will be removing all bag motors from our robot until the reliability improves. I now think that all vex motors are suspect. Has anyone experiences these issues with the "mini cims?"

Re: Buggy BAG Motors
 

Has anyone experienced problems with the recently shipped BAG motors? In other words was this just a bad batch? If I get replacements from VexPro is that likely to solve the problem?

Re: Buggy BAG Motors
 

We just had the last of ours fail at peachtree this past weekend. Fun times. Especially trying to center a 550 in the mounting plate with as much slop as it has. Vexpro should look at including a centering ring similar to what dustin designed. Even a temporary thing just to align them.

Re: Buggy BAG Motors
 

These bags were from two different orders. One from the KOP and the other from an order shipped 2 weeks ago.

Re: Buggy BAG Motors
 

Team 2410 competed with three BAG motors that we ordered somewhere around week 3 or 4 and, as far as I could tell, we did not experience the symptoms of a buggy bag motor.

Re: Buggy BAG Motors
 

Our robot has three BAG motors: two that drive lead-screws that power our chin-up arms, through 20:1 VersaPlanetary gearboxes; and one that drives our scoop-store-shoot mechanism's tilt control, through a 100:1 VersaPlanetary gearbox and 3.6:1 VEX 20dp gearset, for 360:1 overall ratio. The tilt is back-driveable, and the leadscrews are not.

So far we have not seen any of the failures described in this thread. I have spoken and emailed with Paul a few times about the issue, and believe that his team is diligently pursuing a solution.

BTW, several other things on our robot have been stressed to failure already. The BAG motors have gotten very hot several times, even emitting smoke once or twice, but are still working well. After the drive team reported seeing smoke I took the motors off and measured free Amperes, still normal.

I like the BAG motor design for power and thermal robustness -- my personal theory is that the root cause of the failure mode reported here will ultimately be found to be an armature production process, either winding tension or commutator tang crimping, that is not properly controlled.

Re: Buggy BAG Motors
 

We finally had two fell this past week, after running one through the entire lone star regional and a lot of practice before that with out problems and it's replacement. It's only been our back shooter motor in the 3:1 VP that has failed, the front motor that is in the 1:1 setup has not had an issue. The initial replacement motor failed rather quickly after less than 100 shots. We replaced it with another and it has been running fine through two days of heavy practice.

Re: Buggy BAG Motors
 

Was the replacement motor thaqt failed after 100 shots a recent one from VexPro or one from an earlier batch? We're trying to decide if we can trust BAG motors fresh from VexPro or go though the pain of swapping them out.

Like you, our initial shooter wheel was going through a 3:1 transmission and failed. We replaced it with a MiniCIM which works fine but, of course, weights a lot more.

Re: Buggy BAG Motors
 

The replacement was from the beginning of build season and we had tested with it before as well, it wasn't brand new. VEX is sending us a replacement for the first one that failed. I haven't told them about the second one since it was after COB on Friday night.

Re: Buggy BAG Motors
 

All,

It is imperative that you send the failed, or suspect failed, motors back to us. So far we have only received 3 motors that have actually shown the failure mode described.

I need to send samples of failed motors to CCL this week to get their opinion on root cause. VEX has already formulated our opinion, but we want confirmation from CCL.

Richard is right no with the suspected failure mode as the physical evidence I have so far indicated a winding tension problem.

More importantly, the only failed motors I have are from batch 2491. I do not have any failed samples from batch 2493.

We want to get to the bottom of this as soon as possible but need failed motors back.

To answer an earlier question, no we have not had any reported failed MiniCIM motors other than a couple physically damaged during shipping. To state that all of the VEXpro motors are under suspicion is jumping to conclusions without fact. Please keep this discussion to facts only so we can get to the bottom of this.

Thanks,
Paul

Re: Buggy BAG Motors
 

We will send the defective motors back, however, they are currently in the bag. We will pull them in Baltimore (week 7) and send them back to you. Is there an RMA process or are we on the hook for the shipping? Either way i'm fine with it.

Re: Buggy BAG Motors
 

I can confirm with Paul the all the ones 3098 had issues with not starting back up here and there are also from date code 2491.

Re: Buggy BAG Motors
 

Your enthusiasm and passion for investigating these issues is awesome. It really gives me a lot of faith in the product line, and the people behind it.

Re: Buggy BAG Motors
 

I would not jump to this conclusion. Over the course of multiple regionals, I have not seen a single mini-CIM failure on any team's robot. Weeks of extensive, high load prototyping on this motor from my team only resulted in no more "damage" than a warm motor. The mini-CIM definitely lives up to the CIM's reputation as an abusable workhorse of a motor, and I'm really glad we decided to use them this year.

Re: Buggy BAG Motors
 

The BAG motor we use(d) on our practice machine started exhibiting this behavior on Saturday. Our competition robot was fine as of last weekend, but a design change eliminated the use of the motor altogether, so we'll never know if it's going to fail similarly.

I'll try to get someone to remove the BAG motor from its gearbox and send it to y'all, but this is going to be a crazy week for us, so it may not happen in a useful amount of time.

Re: Buggy BAG Motors
 

As I said, our buggy BAGs are on our competition robot, which we got permission to unbag for display purposes only at the Naples Youth Expo this past weekend... And while it wasn't "work" per se, we didn't get explicit permission to pull 'em, so we left 'em on. We'll send them to you (Paul, not Madison) post-Buckeye.

Re: Buggy BAG Motors
 

A quick Update.

The Bag was not in the bag. It was pulled with the shooter after NC. I have it in hand and will be sending it out Monday. Since I didn't get a reply on this thread, I did a quick search and found the RMA information for Vex. I am linking it below. Those who want to help Vex solve this problem might find it useful.

http://content.vexrobotics.com/docs/...A_Form0711.pdf

Would it be helpful if I tagged the two motors with the observed defects (they are different) or should I just throw them in a box and ship them?

Re: Buggy BAG Motors
 

We just swapped out our shooter's early batch of BAG motors with the latest 2493 BAG motors but sadly those are now showing the same reluctance to start on two out of three. We see it mainly on those Versaplanetaries transmissions with more internal, uneven, resistance. We've thrown in the towel on BAG motors until next season when hopefully this get's worked out. We'll be using 775s from here out.

Re: Buggy BAG Motors
 

I never heard... Is the case short problem on 775's a thing of the past?

Re: Buggy BAG Motors
 

Probably. It doesn't matter to us since our motors are mounted on the shooter's ABS base plate.

Re: Buggy BAG Motors
 

Beware that Vex posted a BAG "fix" that doesn't appear to be correct.
When the fix is applied the springs on ours become too short to work.
Vex tech support told us the fix is not official and shouldn't have been posted.

So just a warning that this probably shouldn't be attempted.
What worries me most is that the "fix" says it:
The "fix" pdf is posted on the Vex website BAG motor page:
http://www.vexrobotics.com/vexpro/motor-controllers/217-3351.html
Under
Technical Specifications
Downloads & Docs BAG Motor Spring Modification Instructions

http://content.vexrobotics.com/vexpro/pdf/217-3351-BAG_MotorSpringModInstructions_20130411.pdf

Re: Buggy BAG Motors
 

...wat?

- Sunny G.

Re: Buggy BAG Motors
 

Mark we have applied the fix to all of our BAG motors without incident. We have also applied the fix to team 2337's robot. Could you post some pictures of the problem you are observing?

Re: Buggy BAG Motors
 

If you wouldn't mind talking to our guy who's applying the fix I would greatly appreciate it.
I've been on the road for events the past 7 weeks.

I'll PM his contact info.

P.S.
Is it possible that the fix has already been applied to some of the BAG motors shipped?
That would explain why the spring ended up too short (double application).

Re: Buggy BAG Motors
 

wouldn't that imply that this was a known issue?

Re: Buggy BAG Motors
 

Hi Mark,
Yes, this fix is official. We have applied this to many motors in the office. Paul personally supervised the modification of several at Michigan State Championship. If your springs do not look like the ones in the guide, they have not been modified.

Can you help us understand what is wrong?

Also, who did you speak to at VEX? I apologize for this miscommunication. It is possible that news of this fix did not reach all our support personnel. I will personally fix this oversight.

-John

Re: Buggy BAG Motors
 

So...to be clear, if we have any BAGS that are of lots other that the 3 identified, are their springs already properly modified?

Re: Buggy BAG Motors
 

Yes, these are the only batches we've identified issues with -- if you have problems with a motor from a lot not previously mentioned, please get in touch with us, ASAP.

You can email me directly jvn@vexrobotics.com.

-John

Re: Buggy BAG Motors
 

John,
Thanks for posting the repair instructions.

1) I took apart my bag motor (unused), 2462BL, one of the units identified as having issues, and found a couple of issues. I'm writing here to potentially help others.

2) I did not find the two white spacers on the one side (red one and wave washer present) and the white spacer on the other side. Should I be concerned?

3) I modified the spring clips but the straight side appears much shorter than in your picture (FYI). This made it a big trickier to put back together but it was possible.

Will watch for your response. You and the VEX team must be crazy busy now getting ready for St. Louis.

Re: Buggy BAG Motors
 

And Vex Worlds which start tomorrow. :rolleyes:

Re: Buggy BAG Motors
 

Mark,

The white spacers are used for axial tolerance stack up (in addition to the wave washer). Base on the housing, case, and rotor tolerances there could be 0, 1, 2, or 3 total washers. The majority of the motors have 2 or 3 washers but you should not be concerned if you have less.

Paul


P.S. - And, yes we are a bit crazy over here as my entire staff (save one customer support person) is in Anaheim preparing for the VEX World Championships. Doors open today at 1pm to over 700 middle school, high school, and College teams.